BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a
method for assembling an optical cable. In the optical cable,
a grooved spacer has an elongated plastic rod with a plurality
of spiral grooves in its circumferential surface and optical
fiber ribbons are held within the respective spiral grooves
of the spacer.
Optical cables, in which a grooved spacer has an
elongated plastic rod with a plurality of spiral grooves in
its circumferential surface and optical fiber ribbons are held
within the respective spiral grooves, are now widely employed
as a representative example of the optical cable shown in Fig.
9.
Fig. 9(A) is a perspective view of a spacer, Fig. 9(B)
is a transverse sectional view of an optical fiber ribbon, and
Fig. 9(C) is a transverse sectional view of an optical cable.
As shown in Fig. 9, an optical cable comprises a spacer
30, an anti-tension element 31, a plastic molded element 32,
a plurality of spiral grooves 33, optical fiber ribbons 34,
wires 34a, a wire covering 34b, an upper winding tape 35, a
cable core 36, and an outer covering 37.
In this optical cable, the spacer 30 is formed from
the plastic molded element 32 and the anti-tension element 31.
The anti-tension element 31 is formed of a steel wire, a twisted
wire, FRP or the like. The plastic molded element 32 is made
of polyethylene or the like, and has a single or a plurality
of spiral grooves 33 in the periphery of the anti-tension
element 31. In this case, the outer diameter of the spacer
ranges from about 5 m to 30 mm. A plurality of wires 34a is
formed by covering glass fiber of quartz or the like with
ultraviolet curing resin or the like. The optical fiber
ribbons 34 are formed by disposing the plurality of wires 34a
in parallel and then covering all the wires 34a with the wire
covering 34b made of ultraviolet curing or the like.
The optical fiber ribbons 34 are laminated and held
within the spiral groove 33 of the spacer 30, and the upper
winding tape 35 is applied to the outer periphery of the plastic
molded element 32 to make the cable core 36. Then the plastic
or metal outer covering 37 is applied to the perimeter of the
cable core 36 to complete the optical cable. Although there
has been shown an exemplary optical cable in which the laminated
optical fiber ribbons 34 are respectively held within the
spiral grooves 33 of the spacer 30 in Fig. 9, an single optical
fiber ribbon having one wire 34a may be used. Further, the
optical fiber ribbons held within the spiral grooves 33 may
be formed by twisting a plurality of single wires and then
press-winding the single wires. Moreover, the spiral
direction of the spiral groove of the spacer may be set to the
opposite direction to that shown in Fig. 9(A).
In the case of such the optical cable as mentioned above,
a step of holding the optical fiber ribbons within the spiral
grooves of the spacer to manufacture cable cores is called a
cable assembly step. The cable assembly step is carried out
by an optical cable assembly apparatus. Fig. 10 is an
elevational view of a main part of an optical cable assembly
apparatus. The optical cable assembly apparatus comprises a
supply reel 41, supplying a spacer 42, a dancer roller 43, brake
rollers 44, a guide roller 45, a brake mechanism 46, a spacer
paying-out portion 47, a stationary ribbon supply unit 48,
supply reels 49 supplying optical fiber ribbons 50, a gathering
die 51, a gathering portion 53 winding an upper winding tape
52 onto the spacer 42 to make a cable core 54, a guide roller
55, capstan rollers 56, a dancer roller 57, a take-up mechanism
58, a taking-up reel 59, and a taking-up portion 60. In Fig.
10, X - X is a line axis around which the spacer paying-out
portion 47 and the taking-up portion 60 revolve.
A main part of the optical cable assembly apparatus
includes the spacer paying-out portion 47, the stationary
ribbon supply unit 48, the gathering portion 53 and the
taking-up portion 60. The spacer paying-out portion 47
comprises the supply reel 41 and the brake mechanism 46. The
supply reel 41 revolves around the line axis X - X in the
direction of the spiral groove of the spacer 42. The number
of revolutions thereof is in synchronization with the number
of rotations of the spiral groove thereof. The brake mechanism
46 comprises the dancer roller 43, the brake rollers 44 and
the guide roller 45. The brake mechanism 46 is used to apply
back tension to the spacer 42 sent out of the supply reel 41.
That is, the spacer 42 sent out of the supply reel 41 is wound
on the brake rollers 44 via the dancer roller 43, so that the
back tension is applied to the spacer 42. The diameters of the
dancer roller 43 and the brake roller 44 ranges from 600 to
800 mm, and the diameter of the guide roller 45 ranges from
about 100 to 600 mm.
The spacer 42 applied back tension is sent out of the
spacer paying-out portion 47 via the guide roller 45 toward
the gathering portion 53. The difference between speed in
extending the spacer 42 from the supply reel 41 and speed in
transferring the spacer 42 on the brake roller 44 is temporarily
adjusted by displacing the position of the dancer roller 43.
The guide roller 45 is used to make a direction of letting out
the spacer 42 from the brake rollers 44 coincide with the
direction of the line axis X - X.
The spacer 42 sent out of the spacer paying-out portion
47 runs forward along the line axis X - X while rotating on
its center axis. However, as the rotation on its center axis
coincides with the rotation of the spiral groove, the spiral
groove spatially appears stationary even though it runs forward.
Accordingly, the spiral groove of the spacer 42 always stays
at the same position in the circumferential direction.
On the other hand, the optical fiber ribbons 50 are
sent out of a plurality of supply reels 49 and then guided to
the spiral groove of the spacer 42. The plurality of supply
reels 49 are installed in the stationary ribbon supply unit
48 fixed to the ground. The optical fiber ribbons 50 and the
spacer 42 are gathered at the gathering die 51, and then the
upper winding tape 52 is wound thereon in the gathering portion
53. Since the spiral groove of the spacer 42 stays at the same
position in the circumferential direction at the place of the
gathering die 51 of the gathering portion 53, the optical fiber
ribbons 50 can be held within the spiral groove by only guiding
the optical fiber ribbons 50 to the same position. Next, the
upper winding tape 52 is wound on the spacer 42 in the gathering
portion 53 after the optical fiber ribbons 50 are held within
the spiral groove, so that the cable core 54 is completed. In
this case, it may be arranged to hold the spacer 42 with a coarse
winding element or the like instead of winding the spacer 42
with the upper winding tape 52.
The cable core 54 completed in the gathering portion
53 runs forward to the taking-up portion 60. The taking-up
portion 60 comprises the take-up mechanism 58 and the taking-up
reel 59, and revolves around the line axis X - X in
synchronization with the revolution of the spacer paying-out
portion 47. The take-up mechanism 58 is used to add a take-up
force to the cable core 54. The tale-up mechanism 58 comprises
the guide roller 55, the capstan rollers 56 and the dancer roller
57. The cable core 54 that has entered the take-up mechanism
58 of the taking-up portion 60 along the line axis X - X is
wound on the capstan rollers 56 via the guide roller 55.
Then the cable core 54 is wound on the taking-up reel
59 via the dancer roller 57. In this case, the guide roller
55 is used to guide the cable core 54 to the capstan rollers
56. The capstan rollers 56 is used to add the take-up force
to the cable core 54. The dancer roller 57 is used to
temporarily adjust the difference between speed in taking up
the cable core 54 on the capstan rollers 56 and speed in winding
the cable core 54 on the taking-up reel 59.
Since the spacer is the plastic molded element having
the high rigid anti-tension element in its central part and
quite a thick rod body having a diameter of 5 mm - 30 mm, it
has substantially great bending rigidity. Consequently, the
spacer wound on the supply reel has an extremely strong winding
habit. When it is attempted to bend a longitudinally part of
the spacer in a direction opposite to a winding direction of
the spacer wound on the supply reel, a bending force is generated
which is directed in a direction against the winding habit,
and then rotational force on the center axis is caused to that
part of the spacer thereby. Accordingly, the spacer rotates
on the center axis, and then twisting is generated thereto.
As the twisting of the spacer is generated between the
roller used to give bending in the opposite direction to the
winding direction and another roller in front of or behind it,
the spacer between them undergoes variation in the spiral pitch
of the spiral groove. Further, the cable core also has a strong
winding habit because the optical fiber ribbons, which is held
within the spiral groove of the spacer to make the cable core,
have substantially no effect on the bending rigidity of the
spacer. Accordingly, the twisting is generated to the cable
core as in the case when the spacer is bent in the direction
against the winding habit of the cable core.
On the other hand, the dancer roller 43 and the brake
roller 44 in the spacer paying-out portion 47, and the capstan
rollers 56, the dancer roller 57 and the taking-up reel 59 in
the taking-up portion 60, as shown in the elevational view of
Fig. 10, are rotated clockwise like the supply reel 41 in order
to extend and wind the spacer 42 or to take up and wind the
cable core 54. On the contrary, the guide roller 45 in the
spacer paying-out portion 47 and the guide roller 55 in the
taking-up portion 60 are rotated counterclockwise in order to
guide the spacer 42 or the cable core 54 thereto.
As a result, the spacer 42 in the portions of the guide
rollers 45 and 55 is subjected to bending in the direction
against the winding habit and the twisting on the center axis
is caused to the spacer 42 or the cable core 54 by the opposite
rotations of the guide rollers 45 and 55. As this twisting of
the spacer 42 or the cable core 54 substantially affects the
gathering portion 53, the spiral pitch of the spiral groove
of the spacer 42 or the cable core 54 in front of and behind
the gathering portion 53 deviates from a normal value, that
is, becomes greater or smaller than the normal value.
Accordingly, when the optical fiber ribbons are held within
the spiral groove of the spacer, the optical fiber ribbons are
to be held in such a state that the spiral pitch of the spacer
has deviated from the normal value.
As the optical fiber ribbons and the spacer are gathered
in such a state that they have been given an allowance for
predetermined expansion and contraction according to a design
thereof, a predetermined back tension is applied to them at
a point of time they pass through the gathering portion. This
back tension is released at the time the cable core has been
wound on the taking-up reel. In this case, the back tension
is determined so that the optical fiber ribbons may be held
within the spiral groove in a manner that they give an allowance
for predetermined expansion and contraction with respect to
the spacer.
The optical fiber ribbons held within the spiral groove
of the spacer have the stranding ratio which obtained from the
distance between the position of the optical fiber ribbons and
the center axis of the spacer, and the spiral pitch. The
optical fiber ribbons are set longer than the spacer by a length
equivalent to the stranding ratio. Accordingly, if the spiral
pitch of the spiral groove varies, the length of the optical
fiber ribbons held in the spiral groove also varies.
If the spacer passes through the gathering portion with
the spiral pitch fluctuated due to the twisting and then the
optical fiber ribbons are held within the spiral groove, the
length of the optical fiber ribbons held therein deviates from
the normal value by the length equivalent to the fluctuation
of the spiral pitch. Further, if the cable core is wound on
the taking-up reel in the state above-mentioned and then the
spiral pitch is returned to the original state since the cable
core is released from the twisting at the taking-up portion,
the deviation of the expansion and contraction of the optical
fiber ribbons from the normal value becomes apparent due to
fluctuations in the length of the optical fiber ribbons. If
the expansion and contraction of the optical fiber ribbons
greatly deviate from the normal value, the aging of the optical
fiber ribbons will be shortened, the transmission loss of the
optical fiber ribbons will be increased, and therefore the
quality of the cable cores and the optical cables manufactured
therefrom will be deteriorated.
As set forth above, if the spacer or the cable core
is passed through the rollers that provide bending in the
direction against the winding habit, it undergoes the twisting.
Further, if the twisting affects the gathering portion, the
quality of optical cables will be deteriorated.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to
provide an apparatus and a method for assembling an optical
cable, wherein it is possible to prevent the twisting of a spacer
or a cable core in a gathering portion which results from the
winding habit of the spacer during assembling cables.
The above-mentioned object can be achieved by an
apparatus for assembling an optical cable along a line axis
comprising:
a spacer paying-out portion, having a supply reel on
which a grooved spacer having an elongated plastic rod with
a plurality of spiral grooves in its circumferential surface
is wound, rotational direction for paying-out the spacer
therefrom while revolving around a line axis; a stationary supply unit for supplying a plurality of
optical fiber ribbons to be inserted into respective spiral
grooves of the spacer; a gathering portion for inserting and holding the
optical fiber ribbons in the respective spiral grooves of the
spacer running forward and rotating on its center axis to form
a cable core; a taking-up portion, having a taking-up reel on which
the cable core is, for winding the cable core on the taking-up
reel while revolving around the line axis; a first winding roller rotating in a rotational
direction identical to the rotational direction of the supply
reel of the spacer, for winding the spacer, the first winding
roller being disposed substantially and adjacently before the
gathering portion in a spacer conveying direction; and a second winding roller rotating in a rotational
direction identical to the rotational direction of the supply
reel of the spacer, for winding the cable core, the second
winding roller being disposed substantially and adjacently
after the gathering portion in the spacer conveying direction, wherein the first and second winding rollers are
revolved around the line axis in synchronization with the
revolution of the spacer paying-out portion.
In the above-mentioned construction, the first or second
winding roller is installed adjacently before and after the
gathering portion, that is, installed between the gathering
portion and places where the spacer is wound on any one of
the first and second rollers in the front of or behind the
gathering portion.
It is preferable that the first and second winding
rollers are respectively installed in the spacer paying-out
portion or the taking-up portion.
It is also preferable that the first or second winding
roller may be installed between the spacer paying-out portion
or the taking-up portion and the gathering portion. With this
installation of the first and second winding rollers, the
spacer is not given bending in a direction against the winding
habit of the spacer in front of and behind the vicinity of
the gathering portion. Accordingly, it is possible to
prevent the twisting of the spacer and to stabilize the length
of optical fiber ribbons to be held within the spiral groove
of the spacer. As a result, it is possible to prevent the
transmission characteristics of the optical fiber ribbons
from being deteriorated.
Further, provision of the first or second winding roller
in the spacer paying-out portion or the taking-up portion
makes it possible to use the facilities for revolving the
winding roller in common with those for revolving the spacer
paying-out portion or the taking-up portion, thus resulting
in reducing the facility cost.
Further, In the above-mentioned construction, it is
preferable that each of the first and second winding roller
comprises a rotary roller with a roller surface on which one
of the spacer and the cable core is wound, the rotary roller
having a side roller for pushing the one along the roller
surface in parallel with an rotational direction of the rotary
roller.
It is also preferable that each of the first and second
winding rollers comprises a rotary roller with a fleeting ring
which is rotatably fitted onto a roller surface of the rotary
roller.
The use of the rotary roller with the side roller as
the winding roller or the rotary roller with the fleeting roller
can suppress centrifugal force resulting from the revolution
around the line axis in comparison with the use of the winding
roller using the combination of plurality of rollers, and make
it possible to reduce the facility cost due to the use of only
one rotary. Moreover, the outgoing wire direction can be
stabilized by preventing the incoming and outgoing wire
directions of the spacer from being same direction on top of
each other. Further, provision of the fleeting ring as the
winding roller makes it possible to prevent from giving damage
to the spacer because the fleeting ring pushes the spacer with
the surface thereof. Moreover, the winding roller may comprise
more than one roller and wherein the spacer or the cable core
is stretched across and wound on the rollers.
The above-mentioned object can be also achieved by an
apparatus for assembling an optical cable along a line axis,
the apparatus comprising:
a spacer paying-out portion, having a supply reel on
which a grooved spacer having an elongated plastic rod with
a plurality of spiral grooves in its circumferential surface
is wound, for paying-out the spacer therefrom while revolving
around a line axis; a stationary supply unit for supplying a plurality of
optical fiber ribbons to be inserted into respective spiral
grooves of the spacer; a gathering portion for inserting and holding the
optical fiber ribbons in the respective spiral grooves of the
spacer running forward and rotating on its center axis to form
a cable core; a taking-up portion, having a taking-up reel on which
the cable core is, for winding the cable core on the taking-up
reel while revolving around the line axis; a first winding roller rotating in a rotational
direction identical to the rotational direction of the supply
reel of the spacer, for winding the spacer, the first winding
roller being disposed in the spacer paying-out portion; and a second winding roller rotating in a rotational
direction identical to the rotational direction of the supply
reel of the spacer, for winding the cable core, the second
winding roller being disposed in the taking-up portion, wherein both the first and second winding rollers are
rotated in a rotational direction which is coincided with the
rotational direction of the supply reel.
For instance, a dancer roller or a capstan roller can
serve as the winding roller without installing the winding
roller by changing the outgoing wire position of the dancer
roller or the incoming wire position of the capstan roller,
so that the facility cost also becomes reducible.
Moreover, the above-mentioned object can be attained by
a method for assembling an optical cable along a line axis,
the method comprising steps of:
(a) supplying a grooved spacer having an elongated
plastic rod with a plurality of spiral grooves on its
circumferential surface from a supply reel rotating in a
rotational direction while rotating the spacer about its
center axis, the supply reel being disposed in a spacer
paying-out portion which revolves around the line axis; (b) supplying optical fiber ribbons from a stationary
ribbon supply unit; (c) winding the spacer on a winding roller rotating in
a rotational direction identical to the rotational direction
of the supply reel while revolving around the line axis in
synchronization with the revolution of the spacer paying-out
portion; (d) guiding the optical fiber ribbons into the spiral
grooves respectively and then holding the optical fiber
ribbons within the spiral grooves respectively so as to form
a cable core in a gathering portion; (e) winding the cable core on a winding roller rotating
in an rotational direction identical to the rotational
direction of the supply reel and revolving around the line
axis in synchronization with the revolution of the spacer
paying-out portion; and (f) winding the cable core on a taking-up reel in a
taking-up portion while revolving around the line axis in
synchronization with the revolution of the spacer paying-out
portion.
In the above-mentioned method, it is advantageous that
the method further comprising the steps of:
making a direction of the spacer coincide with the line
axis before the step (c); and making a direction of the cable core coincide with the
line axis before the step (e).
With this above-mentioned method, the spacer is not given
bending in a direction against the winding habit of the spacer
in front of and behind the vicinity of the gathering portion.
Accordingly, it is possible to prevent the twisting of the
spacer and to stabilize the length of optical fiber ribbons
to be held within the spiral groove of the spacer. As a result,
it is possible to prevent the transmission characteristics
of the optical fiber ribbons from being deteriorated.
Other objects, features and advantages of the invention
will be evident from the following detailed description of
the preferred embodiments described in conjunction with the
attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1(A) is an elevational view of a main part of an
embodiment of an optical cable assembly apparatus according
to the present invention, and Figs. 1 (B), (C) and (D) are
a perspective, an elevational and a side view of an example
of winding roller for use in the assembly apparatus according
to the present invention;
Fig. 2 is a.plan, an elevational and a side view of
rollers in a case where the rotational directions of rollers
are identical;
Fig. 3 is a plan, an elevational and a side view of
rollers in another case where the rotational directions of
rollers are identical;
Fig. 4 is a plan, an elevational and a side view of
rollers in a case where the rotational directions of rollers
are opposite to each other;
Fig. 5 is an elevational view of a main part of another
embodiment of optical cable assembly apparatus according to
the present invention;
Figs. 6(A), (B) and (C) are a perspective, an
elevational and a side view of another example of a winding
roller for use in the optical cable assembly apparatus
according to the present invention;
Figs. 7(A), (B) and (C) are a perspective, an
elevational and a side view of still another example of a winding
roller for use in the optical cable assembly apparatus
according to the present invention;
Fig. 8 is an elevational view of a main part of still
another embodiment of optical cable assembly apparatus
according to the present invention;
Fig. 9(A) is a perspective view of a spacer for use
in an optical cable, Fig. 9 (B) is a transverse sectional view
of optical fiber ribbons for use in an optical cable, and Fig.
9 (C) is a transverse sectional view of an example of an optical
cable;
Fig. 10 is an elevational view of a main part of a
conventional optical cable assembly apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred referring to the accompanying drawings,
embodiments of the present invention will now be described.
Fig. 1(A) is an elevational view of an embodiment of
a main part of an optical cable assembly apparatus of the present
invention. Figs. 1(B), (C) and (D) are a perspective, an
elevational and a side view of an embodiment of a winding roller
used in the assembly apparatus shown in Fig. 1(A). In Fig. 1,
the assembly apparatus comprises a supply reel 1 supplying a
spacer 2, a dancer roller 3, brake rollers 4, a guide roller
5, a brake mechanism 6, a spacer paying-out portion 7, winding
rollers 8 and 8', a roller surface 8a, a collar 8b, side rollers
8c, roller arms 8d, a stationary ribbon supply unit 9, supply
reels 10 supplying optical fiber ribbons 11, a gathering die
12, an upper winding tape 13, a gathering portion 14 winding
an upper winding tape 13 onto the spacer 2 to make a cable core
15, a guide roller 16, capstan rollers 17, a dancer roller 18,
a take-up mechanism 19, a taking-up reel 20, and a taking-up
portion 21. In Fig 1, X - X is a line axis around which the
spacer paying-out portion 7 and the taking-up portion 21
revolve.
A main part of the optical cable assembly apparatus
includes the spacer paying-out portion 7, the stationary ribbon
supply unit 9, the two winding rollers 8 and 8', the gathering
portion 14, and the taking-up portion 21. This optical cable
assembly apparatus is similar to optical cable assembly
apparatus of the prior art shown in Fig. 10 except the winding
rollers 8 and 8'. The spacer paying-out portion 7 comprises
the supply reel 1 and the brake mechanism 6. The supply reel
1 revolves around the line axis X - X in a direction of a spiral
groove of the spacer 2. The number of revolutions thereof is
in synchronization with the number of rotations of the spiral
groove thereof. The brake mechanism 6 is used to apply back
tension to the spacer 2 sent out of the supply reel 1, and
comprises the dancer roller 3, the brake rollers 4 and the guide
roller 5.
The spacer 2 sent out of the supply reel 1 is wound
on the brake rollers 4 via the dancer roller 3 where the back
tension is applied to the spacer 2. Then the spacer 2 is sent
out of the spacer paying-out portion 7 via the guide roller
5. The difference between speed in extending the spacer 2 from
the supply reel 1 and speed in transferring the spacer 2 on
the brake roller 4 is temporarily adjusted by displacing the
position of the dancer roller 3. The guide roller 5 is used
to change the direction of letting out the spacer 2 from the
brake rollers 4 to a direction of the line axis X - X.
The spacer 2 sent out of the spacer paying-out portion
7 is wound on the winding roller 8 more than once. The winding
roller 8 is a rotary roller having the side rollers as shown
in Figs. 1(B), (C) and (D). The winding roller 8 has a roller
surface 8a, a collar 8b on one side edge of the roller surface
8a, and a side rollers 8c. The side rollers 8c pushes the spacer
2 wound on the roller surface 8a in a direction of a shaft of
the rotary roller along the roller surface 8a. A plurality of
side rollers 8c are normally disposed in a circumferential
direction of the roller surface 8a, the side rollers 8c being
supported by a respective roller arms 8d. The structure
without the collar 8b provided on the side edge of the roller
surface 8a may be possible.
The winding roller 8 is revolved around the line axis
X - X in synchronization with and in the same direction of the
revolution of the spacer paying-out portion 7 while making
incoming and outgoing wire directions of the spacer 2 from the
roller surface 8a substantially coincide with the line axis
X - X. The diameter of the roller surface 8a of the winding
roller 8 ranges from 600 to 800 mm. The spacer wound on the
roller surface 8a runs forward so that the winding roller 8
can rotate on the roller axis, and therefore rotational driving
force is not applied to the roller shaft.
Although the three roller arms 8d are used to press
the respective side rollers 8c against the spacer 2 in Figs.
1(B), (C) and (D), the number of roller arms 8d and the number
of side rollers 8c may be more than three. In the case of this
winding roller 8, the incoming and outgoing wire are prevented
from overlapping each other on top of the spacer 2 by adjusting
the positions of the side rollers 8c. Further, the use of the
rotary roller having the side rollers as winding rollers allows
the side rollers 8c to adjust the outgoing direction of the
spacer 2, so that the spacer 2 can be sent out to the next
gathering portion 14 stably without variation of the outgoing
direction.
As shown in Fig. 1(A), the rotational direction of the
supply reel 1 of the spacer paying-out portion 7 is set identical
to the rotational direction of the winding roller 8. In other
words, when the supply reel 1 is rotating clockwise in the
elevational view of Fig. 1(A), the spacer 2 is also wound on
the winding roller 8 to make the winding roller 8 rotate
clockwise. As described above, the winding roller 8 is
installed adjacently after the spacer paying-out portion 7.
Further, the spacer 2 is wound on the winding roller 8 in a
direction in which the spacer 2 has a winding habit, that is
in a direction identical to the rotational direction of the
supply reel 1. Accordingly, the twisting of the spacer 2 around
its center axis can be prevented from influencing the gathering
portion 14 though the twisting is generated by bending the
spacer 2 in a direction against the winding habit of the spacer
2 with the guide roller 5 of the spacer paying-out portion 7,.
The spacer 2 sent out of the winding roller 8 enters
the gathering portion 14. The twisting of the spacer 2 on its
center axis is removed adjacently after the spacer 2 exits from
the winding roller 8. Then the spacer paying-out portion 7 and
the winding roller 8 are revolved around the line axis X - X,
so that the spacer 2 runs forward while rotating on its center
axis with a predetermined rotational cycle. Accordingly, the
spacer 2 is not subjected to twisting in the vicinity of the
gathering portion 14 and the spiral pitch of the spiral groove
provided in its surface does not vary. Consequently, a length
of the optical fiber ribbon held within the spiral groove will
not change. Accordingly, excellent transmission
characteristics are obtainable from a completed optical cable
because the length of the optical fiber ribbon relative to the
spacer can be stabilized.
The optical fiber ribbons 11 are each sent out of the
plurality of supply reels 10 of the stationary ribbon supply
unit 9 fixed to the ground, guided to the spiral groove in the
surface of the spacer 2 at the gathering die 12 of the gathering
portion 14, and then held therein in the same way as that in
the prior art. After the optical fiber ribbons 11 are held
within the spiral groove of the spacer 2, the upper winding
tape 13 is wound thereon to form the cable core 15. In this
case, it may be arranged to hold the spacer 2 with a coarse
winding element or the like instead of winding the spacer 2
with the upper winding tape 13. However, there may be cases
where laminated optical fiber ribbons are held within the
spiral groove of the spacer 2, where a single optical fiber
ribbon is held therein, and where single optical fiber ribbons
are twisted and held therein, and so on.
The cable core 15 completed in the gathering portion
14 is wound on the winding roller 8' installed between the
gathering portion 14 and the taking-up portion 21. The winding
roller 8' is similar in shape to the winding roller 8 installed
between the spacer paying-out portion 7 and the gathering
portion 14. This winding roller 8' revolves around the line
axis X - X in synchronization with and in the same direction
of the revolution of the spacer paying-out portion 7 while
making the incoming and outgoing wire directions of the cable
core 15 from the roller surface coincide with the line axis
X - X.
The winding roller 8' is used to prevent the twisting
of the spacer 2 from having an effect on the gathering portion
14 on the basis of bending the spacer 2 in a direction against
the winding habit of the spacer 2 developed by the guide roller
16 of the next taking-up portion 21. The twisting generated
on the guide roller 16 can be prevented from being transmitted
to the spacer 2 in the gathering portion 14 by making the
rotational direction of the winding roller 8' also identical
to that of the supply reel 1.
The cable core 15 sent out of the winding roller 8'
enters the taking-up portion 21. The taking-up portion 21
comprises the take-up mechanism 19 and the taking-up reel 20,
and revolves around the line axis X - X in synchronization with
the revolution of the spacer paying-out portion 7. The take-up
mechanism 19 comprises the guide roller 16, the capstan rollers
17 and the dancer roller 18, and is used to add the take-up
force to the cable core 15. The cable core 15 that has entered
the take-up mechanism 19 of the taking-up portion 21 along the
line axis X - X is wound on the capstan rollers 17 via the guide
roller 16, so that the take-up force is added to the cable core
15. Then the cable core 15 is wound on the taking-up reel 20
via the dancer roller 18 while being drawn thereby.
The guide roller 16 is used to change the direction
of the cable core 15 that has entered the take-up mechanism
19 along the line axis X - X so as to introduce the cable core
15 to the capstan rollers 17. The dancer roller 18 is used to
temporarily adjust the difference between speed in taking up
the cable core 15 by the capstan rollers 17 and speed in winding
the cable core 15 on the taking-up reel 20.
Setting of the rotational direction of the supply reel
identical to that of the winding roller will now be described.
In the assembly apparatus shown in Fig. 1(A), as the spacer
paying-out portion 7, the winding rollers 8 and 8' and the
taking-up portion 21 are made to revolve around the line axis
X - X, they appear to be rotating either clockwise or
counterclockwise in front. It is therefore impossible to
define the winding direction of the reels or rollers only by
the clockwise revolution. Accordingly, the winding
direction of the reels or rollers is defined by their rotational
directions the below.
Figs. 2(A), (B) and (C) are a plan, an elevational and
a side view showing a case where an rotational directions
thereof are identical. In Fig. 2, an axis S - S of an A roller
22 and an axis T - T of a B roller 23 are parallel to each other
with the same rotational direction. In this case, the
rotational directions are defined as being identical. Further,
as a linear body 24 in this case is bent by the A roller 22
and B roller 23 in the same direction, its winding habit added
by the A roller 22 is retained on the B roller 23. Moreover,
even though the A roller 22 and B roller 23 revolve around the
line axis X - X synchronously, the rotational directions are
still identical.
Figs. 3(A), (B) and (C) are a plan, an elevational and
a side view showing another example wherein the rotational
directions are identical. In the case of Fig. 3, an axis T -
T of the B roller 23 is slightly tilted relative to an axis
S-S of the A roller 22, that is, not in parallel to the axis
S - S of the A roller 22. Both their rotational directions are
substantially identical. Even when the axis T - T of the B
roller 23 is tilted by an angle of as relatively small as 30°
or less relative to the axis S - S of the A roller 22 and both
their rotational directions are identical, the winding habit
given by the A roller 22 to the linear body 24 is substantially
retained on the B roller 23 and no greater twisting is developed
in the linear body 24. Accordingly, the tilting of the axis
of rotation by that degree makes it possible to assume that
the rotational directions are identical in the present
invention. Further, in this case, even though the A roller 22
and B roller 23 revolve around the line axis X - X synchronously,
the rotational directions are identical remains unchanged.
Figs. 4(A), (B) and (C) are a plan, an elevational and
a side view showing an example wherein the rotational
directions are opposite to each other. In the case of Fig. 4,
the directions of an axis S - S of the A roller 22 and an axis
T - T of the B roller 23 are parallel to each other, and the
rotational directions of them are opposite to each other. The
rotational directions are also opposite to each other in this
case. In the case of Fig. 4, bending force in a direction
against the winding habit given by the A roller 22 to the linear
body 24 is added to the linear body 24 on the B roller 23, and
therefore the linear body 24 is subjected to twisting when it
passes the B roller 23.
In the optical cable assembly apparatus of Fig. 1(A),
the rotational directions of the supply reel 1 and the winding
rollers 8 and 8' are set identical as shown in Figs. 2 and 3
that have already been described. Moreover, the rotational
directions of the dancer roller 3 and the dancer roller 4 in
the spacer paying-out portion 7, and the capstan rollers 17,
the dancer roller 18 and the taking-up reel 20 in the taking-up
portion 21 are also identical to the rotational directions of
the supply reel 1.
Fig. 5 is an elevational view of a main part of another
embodiment of optical cable assembly apparatus of the present
invention wherein elements similar to the elements of the
optical cable assembly apparatus in Fig. 1 are given same
reference numbers. The optical cable assembly apparatus of Fig.
5 is different from the optical cable assembly apparatus of
Fig. 1(A) in the following points. Although the winding
rollers 8 and 8' in Fig. 1 are respectively installed between
the spacer paying-out portion 7 and the gathering portion 14,
and between the gathering portion 14 and the taking-up portion
21, the winding rollers 8 and 8' in Fig. 5 are respectively
installed inside the brake mechanism 6 and the take-up
mechanism 19. With this arrangement further, the guide roller
5 installed in the brake mechanism 6 and the guide roller 16
installed in the take-up mechanism 19 in Fig. 1(A) are not used
in Fig. 5.
In the optical cable assembly apparatus of Fig. 5, the
incoming and outgoing wire directions of the winding rollers
8 and 8' coincide with the line axis X - X, and the winding
rollers 8 and 8' also revolve around the line axis X - X in
coincide with the respective revolutions of the brake mechanism
6 and the take-up mechanism 19 on the line axis X - X. Moreover,
the rotational directions of the winding rollers 8 an 8' and
the supply reel 1 are made identical, and the spacer 2 and the
cable core 15 are wound on the respective winding rollers 8
and 8' more than once.
The specific shapes of the winding rollers 8 and 8'
in the optical cable assembly apparatus of Fig. 5 are identical
to those shown in Figs. 1(B), (C) and (D). In the case of the
optical cable assembly apparatus shown in Fig. 5, the spacer
2 is not bent in a direction against the winding habit of the
spacer 2 because the rotational directions of all of the rollers
and reels are identical. Accordingly, no bending in a
direction against the winding habit, and therefore no twisting
of the spacer 2 is produced thereby. Naturally, no variation
in the stranding ratio of the optical fiber ribbon relative
to the spacer which is generated by the twisting of the spacer
occurs, and thereby no the deterioration of transmission
characteristics of the optical fiber ribbon occurs.
Figs. 6 and 7 show other cases where winding rollers
in stead of the winding roller 8 described in Figs. 1(B), (C)
and (D) above are usable. Fig. 6 shows an example of a winding
roller having a fleeting ring, and Fig. 7 shows an example using
a winding roller having a plurality of rollers. Figs. 6(A),
(B) and (C) are a perspective, an elevational and a side view
showing a winding roller using such a fleeting ring and a spacer
2. In Figs. 6(A), (B) and (C), a winding roller 25 comprises
a roller surface 25a and a fleeting ring 25b.
The fleeting ring 25b is a ring that is rotatably fitted
onto the roller surface 25a of the winding roller in a such
a condition which it is tilted with respect to a direction
vertical to a roller axis of the winding roller. The fleeting
ring 25b makes the spacer 2 wound on the roller surface 25a
slide on the roller surface 25a in the axial direction of the
winding roller by pushing the spacer, so that the incoming and
outgoing wire directions of the spacer synchronize with the
line axis X - X. In the case of the winding roller 25, the
winding roller 25 is also revolved around the line axis X -
X in synchronization with that of the spacer paying-out portion
while making the incoming and outgoing wire directions
substantially coincide with the line axis X - X. The winding
roller 25, as shown in Fig. 6(B), is rotated clockwise in the
elevational view thereof, and the rotational direction of the
winding roller 25 is made identical to that of the supply reel
of the spacer 2.
Since the winding roller 25 has the fleeting ring 25b,
it is capable of shifting the respective spacer positions on
the outgoing wire side and the incoming wire side without
holding the spacer with the side roller as in the case of the
winding roller 8. Further, the incoming and outgoing wire
directions of the spacer are stabilized so as not to both
directions being same, that is the incoming and outgoing wires
may not be overlapped to each other. The spacer is prevented
from being damaged because the fleeting ring 25b pushes the
spacer 2 with the surface thereof. Moreover, the winding
roller 25 is made rotatable on the roller axis by moving forward
the spacer wound on the roller surface 25a and therefore applies
no rotational driving force to the roller shaft.
Figs. 7(A), (B) and (C) are a perspective, an
elevational and a side view showing a winding roller using a
plurality of rollers. In Figs. 7(A), (B) and (C), a winding
roller 26 comprises a first roller 26a, a second roller 26b,
a third roller 26c and a coupling member 26d. In the case of
the winding roller 26, the first and third rollers 26a and 26c
are set parallel to each other and coupled to the second roller
26b with the coupling member 26d, so that the spacer 2 is
stretched and moved forward from the first roller 26a to the
third roller 26c via the second roller 26b.
Then the winding roller 26 is revolved on line axis
X - X in synchronization with and in the same direction of
revolution of the spacer paying-out portion while making the
incoming and outgoing wire directions coincide with the line
axis X - X. The rotational directions of the rollers of the
winding roller 26 are made identical to that of the supply reel,
and the winding direction of the spacer 2 is such that as shown
in the elevational view of Fig. 7(B), that is the spacer is
wound on each of the rollers which rotate clockwise and moved
clockwise on the rollers.
Each roller of the winding roller 26 is made rotatable
on the roller axis by moving forward the spacer wound on the
three roller surfaces and therefore applies no rotational
driving force to each roller shaft. Further, the direction of
the axis of the second roller 26b is slightly tilted with respect
to the directions of roller axis of the first and third rollers
26a and 26c, so that the spacer 2 can smoothly run across them.
Although the winding roller having a combination of three
rollers has been shown in the example of Fig. 7, two rollers
or more than three rollers in combination may be used to
constitute the winding roller.
Fig. 8 is an elevational view of a main part of still
another embodiment of an optical cable assembly apparatus of
the present invention wherein elements similar to the elements
of the optical cable assembly apparatus in Fig. 1 are given
the same reference numbers. This optical cable assembly
apparatus includes a first capstan roller 17a and a turnroller
27. The turnroller 27 is a roller for use in changing a
direction of a spacer 2, and an outgoing wire direction of the
turnroller 27 coincides with a line axis X - X. Moreover, an
incoming wire direction of the first capstan roller 17a of a
capstan roller 17 is made to coincide with the line axis X -
X.
When a spacer paying-out portion 7 and a taking-up
portion 21 are revolved around the line axis X - X, the spacer
2 sent out of the turnroller 27 moves forward while rotating
on its center axis. Then the spacer 2 becomes the cable core
15 via the gathering portion 14 before entering the first
capstan roller 17a. In the optical cable assembly apparatus
of Fig. 8, as in the optical cable assembly apparatus shown
in Fig. 5, the rotational directions of the dancer roller 3,
the brake roller 4 and the turnroller 24 installed in the brake
mechanism 6, and the rotational directions of the capstan
roller 17, the dancer roller 18 and the taking-up reel 20 are
also identical to that of the supply reel 1.
Accordingly, the spacer 2 is bend in the same direction
as that of the winding habit given to the spacer 2 on the supply
reel 1, so that no twisting can be caused to the spacer 2 by
accepting. As the number of rollers in the optical cable
assembly apparatus shown in Fig. 8 is smaller than that in the
optical cable assembly apparatus shown in Fig. 5, the optical
cable assembly apparatus shown in Fig. 8 can be produced less
costly.
The optical cable assembly apparatus according to the
present invention comprises the spacer paying-out portion
revolving around the line axis, the stationary ribbon supply
unit, the gathering portion, and the taking-up portion
revolving around the line axis. The winding roller having an
rotational direction identical to the rotational direction of
the supply reel of the spacer is installed adjacently before
and after the gathering portion. Further, the winding roller
is revolved around the line axis in synchronization with the
revolution of the spacer paying-out portion, and the spacer
or the cable core is wound on the winding roller. Consequently,
no bending is given to the spacer in a direction against the
winding habit of the spacer in front of and behind the gathering
portion, and therefore it is able to prevent the twisting of
the spacer, to stabilize the length of optical fiber ribbons
to be held within the spiral groove of the spacer and to prevent
the transmission characteristics of the optical fiber ribbons
from being deteriorated.
Further, provision of the winding roller in the spacer
paying-out portion or the taking-up portion makes it possible
to use the facilities for revolving the winding roller in common
with those for revolving the spacer paying-out portion or the
taking-up portion, thus resulting in reducing the facility cost.
Moreover, the dancer roller or the capstan roller can serve
as the winding roller without installing the winding roller
by changing the outgoing wire position of the dancer roller
or the incoming wire position of the capstan roller, so that
the facility cost also becomes reducible.
The use of the rotary roller with the side roller as
the winding roller or the rotary roller with the fleeting roller
can suppress centrifugal force resulting from the revolution
around the line axis in comparison with the use of the winding
roller using the combination of plurality of rollers, and make
it possible to reduce the facility cost due to the use of only
one rotary. Moreover, the outgoing wire direction can be
stabilized by preventing the incoming and outgoing wire
directions of the spacer from being same direction on top of
each other.
Although the invention has been described in its
preferred form and structure with a certain degree of
particularity, it is understood that the present disclosure
of the preferred form can be changed in the details of
construction and in the combination and arrangement of parts
without departing from the spirit and the scope of the
invention as hereinafter claimed.